From: Wei Yongjun <[email protected]>

commit 71e843295c680898959b22dc877ae3839cc22470 upstream.

kmemleak report memory leak as follows:

  unreferenced object 0x607ee4e5f948 (size 8):
  comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s)
  hex dump (first 8 bytes):
  00 00 00 00 00 00 00 00 ........
  backtrace:
     relay_open kernel/relay.c:583 [inline]
     relay_open+0xb6/0x970 kernel/relay.c:563
     do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557
     __blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597
     blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738
     blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613
     block_ioctl+0xe5/0x120 fs/block_dev.c:1871
     vfs_ioctl fs/ioctl.c:48 [inline]
     __do_sys_ioctl fs/ioctl.c:753 [inline]
     __se_sys_ioctl fs/ioctl.c:739 [inline]
     __x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739
     do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

'chan->buf' is malloced in relay_open() by alloc_percpu() but not free
while destroy the relay channel.  Fix it by adding free_percpu() before
return from relay_destroy_channel().

Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel 
buffer pointers")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Wei Yongjun <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Daniel Axtens <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Akash Goel <[email protected]>
Cc: <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 kernel/relay.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -197,6 +197,7 @@ free_buf:
 static void relay_destroy_channel(struct kref *kref)
 {
        struct rchan *chan = container_of(kref, struct rchan, kref);
+       free_percpu(chan->buf);
        kfree(chan);
 }
 


Reply via email to